L61IZ; . 



J -^ 



EXPERIMENTAL STUDY OF 

MOTOR ABILITIES OF CHILDREN IN 

THE PRIMARY GRADES 



BY 
BUFORD JENNETTE JOHNSON 



A DISSERTATION 

Submitted to the Board of University Studies of The Johns 

Hopkins University in Conformity with the Requirements 

for the Degree of Doctor of Philosophy 

1916 



Baltimore 

The Johns Hopkins press 

1917 



EXPERIMENTAL STUDY OF 

MOTOR ABILITIES OF CHILDREN IN 

THE PRIMARY GRADES 



EXPERIMENTAL STUDY OF 

MOTOR ABILITIES OF CHILDREN IN 

THE PRIMARY GRADES 



BY 
BUFORD JENNETTE JOHNSON 



A DISSERTATION 

Submitted to the Board of University Studies of The Johns. 

Hopkins University in Conformity with the Requirements 

for the Degree of Doctor of Philosophy 

1916 



Baltimore 

The Johns Hopkins press 

1917 






PRESS OF 

THE NEW ERA PBINTING COMPANY 

LANCASTER. PA 



KCV 16 I9I7 



CONTENTS 

Page 

Acknowledgments vii 

Introduction 9 

Historical 11 

General Method of Experimental Procedure 16 

Experimental Results : 

Rate of Voluntary Movements 18 

Steadiness of Motor Control 31 

Reaction Times 36 

Accuracy of Movement 41 

Preference in Side of Body Used 53 

General Summary and Conclusions 56 

Bibliography 60 



ACKNOWLEDGMENTS 



The writer is under heavy obligations to many who have 
materially aided her in this work. She is especially in- 
debted to Dr. Knight Dunlap, Professor of Experimental 
Psychology at The Johns Hopkins University, who devised 
apparatus and gave suggestions and criticisms throughout 
the work; to Dr. E. F. Buchner, Professor of Education 
at The Johns Hopkins University, for valuable assistance 
in arranging for the carrying on of the work in the schools ; 
to the principals and teachers of the schools visited for their 
co-operation. 



vu 



EXPERIMENTAL STUDY OF MOTOR ABILITIES 
OF CHILDREN IN THE PRIMARY GRADES 



I. INTRODUCTION 

The careful study of motions made by adults in the in- 
dustrial vocations has served to give a scientific basis for 
almost revolutionary policies and methods in the economic 
world. The popular question of vocational guidance in- 
volves various tests of motor ability and control. 

The more important investigations of motor abilities and 
of learning processes have concerned adult activities. In- 
quiries including tests of adolescents and of school children 
in the elementary grades have usually been limited to the 
single test or to a few repetitions. For a study of indi- 
vidual variation in meeting new situations, as indicative of 
previous experience, or for detecting extremes in the normal 
range of distribution, the single test is most valuable. For 
the larger number in the middle range, it is generally agreed 
that special practice makes a measurement of a process a 
far truer one. 

Because of their attitude to the novelty of the experi- 
ment, with young children it is almost impossible to ob- 
tain results from single tests that will give any positive 
indication of actual motor abilities. The tendency to over- 
estimate the value of results obtained from particular ex- 
periments becomes dangerous when these results are uni- 
versally applied and used to justify some procedure, such 
as for diagnostic purposes in vocational guidance. 

The problem of this investigation is the determination 
of motor abilities of children between the ages of four and 
ten years, dealing specifically with the improvement by 
practice in motor-coordination and the effect upon the 

9 



jQ MOTOR ABILITIES OF CHILDREN 

learning process of different intervals between practice 
periods. Rate and precision of voluntary movement, meas- 
urement of involuntary movement, simple and discriminative 
reaction times are treated. Sex differences, fatigue effects, 
and preference in hand used are also studied. 



II. HISTORICAL SKETCH 

There is no scarcity of data as to tests of the kind under- 
taken, but varying technique and purposes have given a 
preponderance of unconfirmed experimental results. 

I. Speed of Movement 

(i) Practice Effects. 

Results of the tapping test used with adults in practice 
series by HoHingworth (ii)/ Wells (21), Marsh (16), 
and Dresslar (7), show improvement due to practice, vary- 
ing in rate and amount with individuals, conditions, and 
duration of experiment. The rate is not uniform. Wells 
(21) reporting that the curve fluctuates more after a week 
than at the beginning. HoHingworth (11) concludes that 
there is very low correlation of first trial with final capacity. 
All previous investigators show that rate increases with 
age, with some evidence of retardation at periods of retarded 
physical growth. No prolonged experimental work has 
been done with children so far as the writer knows. 
(2) Sex Differences. 

Bryan (5) found that in single tests on children from 
five to sixteen years old boys were slightly superior, except 
at thirteen when the girls excelled. This latter finding, as 
was suggested in his paper, might be explained by the 
earlier maturity of the girls. 

Bolton (4) studied rapidity of movement in groups 
selected according to social status. Tapping with finger 
on key was form of test used. Five trials with each hand, 
duration of each trial 5 seconds, constituted an experiment. 
Records of one experiment for thirty of each sex, eight to 
nine years old, belonging to a superior social group, were 

1 The numbers in parentheses refer to the list of references given 
in the BibHography. 

II 



12 MOTOR ABILITIES OF CHILDREN 

compared with those for the same number of inferior 
social standing. He concludes that "girls are uniformly 
better than the boys. The girls in the good class do not 
show greater or even quite as much superiority over the 
boys of the same class, as the girls of the poor class show 
over the boys of the same class." 

Gilbert (8) gave single tests with right hand to one 
hundred children of each age, fifty of each sex, from six 
to seventeen years old. Rapidity was measured by tapping 
on telegraph key in connection with chronoscope for forty- 
five seconds. Records were taken only of first five and 
last five seconds. He found that boys excel in speed. He 
gave similar tests to Iowa school children. Results there 
showed a slight superiority for girls during the earlier 
years. 

For ages twelve and a half to thirteen and a half years 
Burt and Moore (6) found that 69.8% of boys exceeded 
median speed of girls. Among adults, Thompson (20) 
found that 88% of men tested exceeded the median speed 
of women. 

(3) Fatigue Effects. 

Wells (21) found among adults that practice brings 
warming up, showing in increased immunity to fatigue, and 
that initial rate and fatigue loss are negatively correlated. 

Dresslar (7) reports that with subject working at "hmit 
of practice" sensations of fatigue ceased, but objective 
phase persisted. 

Gilbert (8) found that suscej>tibility to fatigue decreases 
uniformly for both sexes with increase in age; that boys 
tire more quickly than girls, but their initial superiority was 
sufficient to over-balance the greater percentage of fatigue 
loss and make their net efficiency greater. Among the 
Iowa children he found practically no difference between 
sexes in fatigue loss during last five years, from twelve to 
seventeen. 

(4) Index of Right-handedness. 

Wells (21) reports for adults no greater improvement by 



HISTORICAL SKETCH 1 3 

practice with left hand than right hand, but that right hand 
tends to warm up more than left hand ; hence is more 
immune to fatigue. He finds the relationship between right 
and left hand more variable in women than in men and their 
hands farther apart in ability. These conclusions are based 
upon only two experiments, in first of which women sur- 
passed men with right hand but elsewhere were inferior. 

Woolley and Fischer (23) found superiority in tapping 
test more reliable an indication of left-handedness than 
superior steadiness or strength. 

Bolton (4) found no significant difiference between right 
and left hand for "good" and "poor" subjects. 

2. Involuntary Movement. 

(i) Practice Effects. 

It is generally recognized that there is little improvement 
by practice in steadiness test, unless by a trick in method 
for control of respiration. Since control of muscles to 
prevent moving of body, co-operation of subject, and phys- 
iological processes affect results so greatly, satisfactory 
control, especially for children, is difficult to establish. For 
children of the age considered various forms of tests have 
been used and for varying purposes. No data actually com- 
parable is available, so far as writer is aware. 

Hancock (10) concludes from use of ataxiagraph that 
adults have 5.8 times the control of children from five to 
seven years old. 
(2) Sex Differences. 

Distinct sex differences are not evident. McDonald 
(15) and Hancock (10) found girls steadier than boys. 
In tracing test Bryan (5) reports a slight superiority for 
boys, while Bolton (4) found that girls excel. 

Woolley and Fischer (23) used a form of test similar to 
ours with seven hundred and fifty-three children fourteen 
years old, and one year later three hundred and ninety-two 
boys and two hundred and eighty-seven girls were retested. 
Their conclusion was that "girls are clearly superior to 
the boys in steadiness." 



14 MOTOR ABILITIES OF CHILDREN 

(3) Index of Right-handedness. 

Variations are so great in results and a shift in superiority 
from one hand to another occurs so often that the index of 
right-handedness is not very reliable. Woolley and Fischer 
(23) found forty-eight boys and thirty-one girls superior 
with left hand in first test. Of these, forty-six boys and 
twenty-nine girls were retested a year later. Only ten 
boys and five girls remained left-handed, while twenty-five 
new subjects showed superiority with left hand in second 
test. 

3. Simple and Discrimination Reaction Times 

Gilbert (8) reports reaction times for children from six 
to seventeen years old. The median value for ten trials 
was accounted the measurement of a subject's reaction time. 
Averages of these values were taken to represent the dif- 
ferent ages. Discrimination preceded simple reaction. He 
found boys quicker than girls, except for discrimination re- 
actions at age of six, and a decrease in reaction time with 
increase in age. 

4. Accuracy of Movement 

Probing or thrusting movements in aiming have been 
frequently used for measuring precision, as in Thompson's 
(20) target test on adults, in which she found better co- 
ordination on part of men. 

We have not been able to find any prolonged study of 
children. Bagley (i) studied accuracy in aiming at a 
target — ^bull's eye, 10 mm. in diameter — from a distance of 
two meters. The experiment consisted of three trials, ten 
marbles thrown at a trial. Errors in millimeters as to 
distance from center were computed. Ages of subjects 
varied from eight to seventeen years. He reports that 
"boys slightly surpass the girls in motor ability." There 
is a gradual increase in ability with increasing age. 



historical sketch 1 5 

5. Distribution of Practice Periods in Learning 

Leuba and Hyde (13) made four divisions of subjects in 
testing progress in writing English prose in German script. 
The daily and alternate-day practice groups made better 
records than the twice-per-day or every-third-day groups. 

Lashley (14) found that college boys show greater im- 
provement in skill in archery for practice periods of five 
shots per day, than for a greater number of shots. 

Munn (17) carried out a series of ten substitution tests, 
one test each day, on twelve children of an average age of 
eight years. Six were taken in the morning, six in the 
afternoon, and while slower in the beginning, children 
make greater but more irregular gains than adults. From 
her records of normal school pupils given varying intervals 
between practice periods in this test, she concludes that 
short and frequent practice periods are most valuable. 

Murphy (18) found that normal school girls in practice 
at javelin throwing made greater gains when given weekly 
or alternate-day practice than through a distribution of 
five times per week. 

6. Summary 

As a summary of the main points in the findings of 
previous investigators we may note: 

That all results show a marked increase of motor con- 
trol with age. 

That the majority report a slight sex dijfference in favor 
of boys in rate and accuracy of movement; in favor of 
girls in steadiness. Loss by fatigue is greater for boys and 
these sex differences are more marked with increasing 
chronological age. 

That the index of right-handedness varies with age, 
being more pronounced in childhood. 

That there is disagreement as to the most economical 
distribution of practice periods in learning, but somewhat 
stronger evidence in favor of short and frequent periods, 
with preference given to morning hours for children. 



III. PROCEDURE 

The following tests were made by the writer. Similar 
tests had been given previously both to children and adults 
and satisfactory methods of control and procedure carefully 
studied. 

In the first grade of a public school in Thomson, Georgia, 
where the pupils are of varied social status, such as is 
found in a small Southern town, eighteen girls and sixteen 
boys between the ages of five and nine years were given 
the Steadiness Test on September i6 and 17, 191 5. The 
following Monday at the same hours, from 9 to 12 o'clock, 
a series of tests in tapping were begun and continued 
through three weeks, omitting Saturdays and Sundays. 
The Monday following the completion of this practice series 
in tapping a second steadiness test was given. Detailed 
methods and apparatus are described under the special 
headings for each form of test. 

The measurement of simple and discriminative reaction 
times was made in The Johns Hopkins Psychological Lab- 
oratory. The difficulties in arranging for many children 
to work there caused the number of subjects to be small 
and the distribution such that sex differentiation could not 
be of much value. The study of the factors entering into 
this test upon young children has been highly profitable. 

The tests in precision of movement as measured by aim- 
ing at the center of a system of concentric circles were made 
upon children of the first and second grades of a public 
school in Baltimore. Only normal children, free from 
physical defects as determined by medical inspection, were 
tested. They came from the poorer district of the city 
and in many cases of foreign parentage. These children 
were always eager to take part in the " game." Groups of 

16 



PROCEDURE I 7 

twelve, six boys and six girls, were selected for different 
practice periods, varying from five days successively in one 
week to once in two weeks. Tests were begun November 
29, 1915, and continued until middle of April, 1916. 

Further details of experimental procedure are discussed 
later in connection with results of various forms of tests. 



IV. RATE OF VOLUNTARY MOVEMENTS 

I. Apparatus 

The tapping test similar to that described in Whipple's 
(24) Manual was used for testing quickness of movement. 
The board is a brass plate four inches square. The stylus, 
weighing 19 grams, had a metal needle }^ of an inch in 
diameter, i^ inches long, with a wooden handle 4 inches 
long, ^ of an inch in diameter. Board, stylus, and Ewald 
Chronoscope were so wired with battery that contact of 
stylus with plate recorded a tap. By stop-watch, number 
of seconds required for one hundred taps was scored. 
Time required for first fifty taps was also noted to secure 
an index of fatigue. Kymograph record was not made, but 
rate of children is such the experimenter could count taps 
and thus kept check on record of chronoscope. This 
method is open to criticism as a source of error, but the 
personal equation was the same in each case and the differ- 
ences too small for significant errors. 

2, Method of Conducting Test 

The board was placed upon a table near the edge and 
each child stood during test. In taking position some had 
a tendency to rest free hand upon table but this was not 
permitted. Blocks were used to adjust position of board 
for each individual, so that a comfortable position was 
maintained. Freedom was allowed in use of movement, 
resulting in combination of wrist and elbow. Each child 
was shown how the taps caused the hand to move on the 
"clock," but this was screened from sight during tapping. 
A few preliminary taps were given him in this explanation. 
He was told to tap just as rapidly as possible from the 
signal " Ready Now " to that of " Stop." Right hand was 
tested first. After a rest of thirty seconds, left hand was 
tested. 

18 



RATE OF VOLUNTARY MOVEMENTS I9 

A room adjoining the Assembly Hall, very quiet during 
the hours of experimentation, was available for all the 
tests. Two children were taken at a time. One sat across 
the room from the table and there was no talking or moving 
about during the tapping. Throughout the entire series 
the children seemed ready and eager to tap, except for the 
desire to stop at the onset of fatigue. This desire was 
but poorly controlled by a few with their left hands. 

3. Subjects 

All the pupils from one First Grade room, between the 
ages of five to nine years, began the test, — nineteen girls 
and eleven boys. There were four girls and three boys of 
the higher section, who had been in school the Spring 
before. The others had just entered the first week in 
September. Only nine girls and four boys were present 
each day of the fifteen days on which tests were made. 
There are thirteen girls and six boys whose records are 
reported, their absences ranging only from one to two days. 
Height, standing and with shoes, weight, and age of each 
subject were recorded. In physical measurements they ap- 
proximate closely the norms in stature and weight estab- 
lished by Boas (3) and Smedley (19). The girls averaged 
six years, eight months, twenty-nine and two-thirteenths 
days in age, ranging from five years, ten months, fourteen 
days to seven years, eight months, sixteen days. The boys 
averaged six years, eight months, twenty-six and two- 
thirds days, ranging from six years to seven years, one 
month and twenty-eight days. There is a difference of 
2.48 days in averaged ages, while the range is six months 
greater for girls. 

4. Computation of Results 

The daily averages of time in seconds required for first 
fifty and second fifty taps with each hand were computed 
for both sexes. The learning curves are plotted from 
averages for the complete test, one hundred taps. 



20 MOTOR ABILITIES OF CHILDREN 

The individual averages for entire series were computed. 
With these as measurements the averages and mean varia- 
tions for sex differentiation were made. In other words, 
the average of individual averages was used as measure of 
group. Median value was also found and probable error^ 
obtained for determining significance of averages. 

The difference in daily averages of time required for first 
and second fifty taps was used to indicate loss by fatigue. 

5, Results 

The table below shows the daily averages. T is total 
time for one hundred taps. D is difference in time for 
first and second fifty taps, 
(i) Practice Effects. 

It is clearly shown that there is marked improvement 
with practice. During the first six days a great percentage 
of the entire gain is made. For the next five days there are 
irregularities and the downward tendency of curves for 
the last three days indicates that a somewhat higher final 
level of efficiency would have been attained through further 
practice. 

The average rate from all trials is not attained until the 
sixth day for girls, the fifth day for boys. The initial 
records of girls for one hundred taps ranged from 22 to 45 
seconds with right hand; 25 to 55 seconds with left hand. 
For boys, 26 to 39 seconds, right hand; 34 to 38 seconds, 
left hand. The group of girls had two subjects at each 
extreme and the central group had a range of only 3.5 
seconds as compared with 23 seconds for entire group. The 
group of boys clusters more closely about the median and 
seems of rather mediocre ability when judged by initial 
trials, yet they finally attained a rate, based on time for 
first fifty taps, superior to Gilbert's seven-year-old boys, 
whose records are based on first five seconds. 

1 P. E. was obtained by following formula : P. E. = 0.8453 X A. D., 
where A. D. represents the average deviation from the average of 
individual measurements. 



RATE OF VOLUNTARY MOVEMENTS 



21 



TABLE I 
Showing Daily Averages in Tapping Test 





Boys — Time 


m Seconc 


Is 


Girls — Time in Seconds 


Day 


I St 50 
Taps 


2d 50 

Taps 


Total 


Diff. 


I St 50 
Taps 


2d 50 

Taps 


Total 


Diff. 


I— R.H. 


15-75 


17.25 


33-00 


1.5 


13-58 


15.00 


28.58 


1.42 


L.H. 


15-33 


20.33 


35-66 


5.0 


15.00 


17.29 


32.29 


2.29 


2— R. 


15-30 


15-66 


30.96 


0.36 


12.38 


14-23 


26.61 


1-85 


L. 


15.66 


18.41 


34-07 


2.75 


14-15 


17.30 


31.45 


3-15 


3-R- 


12.33 


13.16 


25-49 


0.83 


II. II 


13-34 


24.45 


2.23 


L. 


14.41 


16.25 


30.66 


1.84 


13-43 


16.20 


29.63 


2.77 


4-R. 


10.00 


13.40 


23.40 


3.40 


10.22 


13.04 


23.26 


2.82 


L. 


12.58 


16.83 


29.41 


4.25 


12. II 


15-47 


27-58 


3-36 


5-R- 


10.15 


12.16 


22.31 


2.01 


10.31 


12.54 


22.85 


2.23 


L. 


13.08 


15-00 


28.08 


1.92 


12.46 


15-19 


27-65 


2.73 


6— R. 


9.66 


12.33 


21.99 


2.66 


9.85 


12.07 


21.92 


2.22 


L. 


12.83 


14.66 


27-49 


1-83 


12.17 


15-24 


27.41 


3.07 


7-R. 


10.13 


12.03 


22.16 


1-9 


9.72 


11-95 


21.67 


2.23 


L. 


12.73 


16.50 


29.23 


3-77 


11.84 


14-73 


26.57 


2.89 


8— R. 


10.13 


12.03 


22.16 


1.90 


9.75 


12.32 


22.08 


2-57 


L. 


12.90 


16.16 


29.06 


3-26 


11.65 


13-71 


25-36 


2.06 


9-R. 


9-58 


13-03 


22.61 


3-45 


9.31 


11.46 


20.77 


2.15 


L. 


12.00 


15-33 


27-33 


3-33 


11.64 


14.74 


26.38 


3-09 


10— R. 


9.66 


11.83 


21.49 


2.17 


9.12 


II. 18 


20.30 


2.06 


L. 


11.83 


14.83 


26.66 


3.00 


11.35 


14.00 


25-35 


0.65 


II— R. 


9-73 


11.43 


21.16 


1.70 


9-57 


11.20 


20.77 


1-63 


L. 


11-83 


15.00 


26.83 


3-17 


II. 10 


13-66 


24.76 


2.55 


12— R. 


9-43 


11.83 


21.26 


2.40 


9.20 


10.87 


20.07 


1.67 


L. 


12.50 


14.16 


26.66 


1.66 


11.47 


13.61 


25.08 


2-15 


I3-R. 


10.10 


12.06 


22.16 


1.96 


9-33 


10.69 


20.02 


1-36 


L. 


12.00 


14.66 


26.66 


2.66 


10.83 


13-53 


24.36 


2.70 


14— R. 


9.72 


12.28 


22.00 


2.56 


9-24 


11.74 


20.98 


2.50 


L. 


11.80 


15.20 


27.00 


3-40 


11.20 


13.16 


24.36 


1.96 


15-R. 


9.40 


11.38 


20.73 


1-93 


8.18 


9-90 


18.08 


1.72 


L. 


13.00 


14.00 


27.00 


1. 00 


II. 10 


12.71 


23-81 


1.61 


Average R. 


10.73 


12.79 


23-52 


2.049 


10.06 


12.10 


22.16 


2.046 


L. 


12.96 


15.82 


28.78 


2.856 


12.10 


14.70 


26.80 


2.469 



Table II shows the individual ranking in first trials and 
in averages obtained as a measure of final efficiency. 

Considering the right hands, it is noticeable that the boys 
making best and poorest records on first trials make the 
least change in final ranking. This same tendency is noted 
in the girls and is more pronounced in the more inefficient 
group. There was no case in which there was no change 
in ranking, this varying from one step to two for boys; 
from one step to six for girls. 



22 



MOTOR ABILITIES OF CHILDREN 




Fig. I. Tapping Test. Abscissa, Practice Periods. Ordinate, Time. 
Boys, R. H. , L. H. . Girls, R. H. , L. H. . 

The averages for left hands show much greater variation 
from initial trials, this being more marked in the extremes 
for the boys, in which group there were no left-handers. 

TABLE II 
Rank in Tapping Test 





R. 


H. 


L. H. 




R. 


H. 


L. H. 


Boys 










Girls 












I St Day 


Average 


ist Day 


Average 




i»t Day 


Average 


ist Day 


Average 


a 


4 


6 


3 


4 


A 


I 


2 


10 


4 


b 


5 


3 


6 


2 


B 


7 


4 


4 


3 


c 


6 


5 


5 


3 


C 


9 


6 


7 


8 


d 


3 


I 


4 


I 


D 


8 


10 


2 


2 


e 


2 


4 


I 


6 


E 


12 


13 


I 


6 


f 


I 


2 


2 


5 


F 


4 


I 


5 


I 












G 


II 


12 


8 


II 












H 


13 


II 


13 


12 












I 


3 


7 


12 


13 












J 


6 


5 


9 


lO 












K 


2 


8 


3 


9 












L 


10 


9 


II 


5 












M 


5 


3 


6 


7 



RATE OF VOLUNTARY MOVEMENTS 



23 



Of the girls D was decidedly left-handed and it is not 
surprising that she kept her rank. E's left hand showed 
slight superiority over right hand in final efficiency, but 
was not consistently so throughout the series and drops 
from I to 6 in rank. Again there are erratic changes in 
ranks varying from i to 6 steps with no general tendency, 
but the two most inefficient of this group make a change 
of but one step. 

These results show clearly that the initial trials are not 
indicative of actual ability but are of diagnostic value in 
detecting the extremes, or greatest variants in the normal 
distribution. 

A comparison of results is not of value unless the vary- 
ing conditions are carefully noted. The following tabula- 
tion for tapping with right hand shows the increase in rate 
with age and sex differences. 



No. Taps 




in I Sec. 


Sex 


6.7 


male 


5.36 


male 


5-28 


female 


4-56 


male 


4-25 


female 


6.1 


male 


6.13 


female 


4.72 


male 


4-25 


female 


4.66 


male 


4-95 


female 



Age 




Duration of 
Trial 



Marsh 

Burt 

Gilbert 

Bolton 

Bolton 

Bryan 

Our average 
rate 



26-34 
I2§-I3i 



8-9 
8-9 

6 

6 

5-8 
5-8 



Time for 100 

Taps 

15 Seconds 



10 

ID 



The validity of the initial trial, or the average of less than 
five trials, as a measure of ability is again questioned by 
certain differences in individual records during early trials. 
It does not seem expedient to give all the individual 
records and curves, but a study of a few of the unusual 
ones suggests the importance of considering some of the 
individual differences that are completely covered up in the 
averages. 

In general the individual curves correspond in form to 



24 



MOTOR ABILITIES OF CHILDREN 



the group curve. The left-handers, as D, having very 
similar curves to a right-hander, save for change of place 
and, perhaps, less distance apart. 

There was one girl, K, whose record for first day was 
better than that for second, third, and fourth days and 
final average, both with right and left hand, though she 




Fig. 2. Subject K. Tapping Test. Abscissa, Practice Periods, 
nate. Time. R. H. , L. H. — . 



Ordi- 



attained a speed on several other days three seconds faster 
than the first day rate. 

Figure 2 shows curve of individual K. If abnormal 
physiological condition prevailed during the three days of 
diminished speed it was not evident. This subject did have 
a cold the second week and the vitality may have been 
lower just preceding it. 

Figure 3 shows curve for I, whose left hand was so 
poorly controlled. Her right hand curve is normal, her 
average for it being median value for group, but the hands 
are very far apart. She seemed to have used her left hand 



RATE OF VOLUNTARY MOVEMENTS 



25 



but little and to be really averse to using it. Her awkward 
holding of stylus with left hand and variation in rate for 
last fifty seconds were noted. There was a tendency when 



40 



35 



30 



25 



IS 



A 

\ / \ 



V. 



.y^^ 



\_ 



\. 



\ 



N/ 




. ^ A 



15 



Fig. 3. Subject I. Tapping Test. Abscissa, Practice Periods. Ordi- 
nate, Time. R. H. , L. H. . 

nearly fifty taps had been made to change from holding 
stylus in fingers to grasping in palm ; to pound slowly upon 
plate, and to move right hand in correspondence with left. 

Figure 4 shows curve for subject H, whose initial rate 
was exceedingly slow and left hand also under poor control. 
There is here a marked resemblance in form of two curves, 
but the hands are far apart. 

Of those tested on the first day who were present as 
many as nine days, four girls and four boys failed to do 
as well on the second day. These records showed much 
irregularity for several days, some not again attaining 
speed of first day until fourth or fifth day. 

Wells's {22) interpretation of difference between first 
and second trials with women, who surpassed men with 



26 



MOTOR ABILITIES OF CHILDREN 



right hand in first trial but were elsewhere inferior, as due 
to affective variability, — a sex characteristic of not being 
SO interested after the novelty had passed away, — is not in 
agreement with these findings for children. It seems not 




Subj ect H. Tapping Test 
nate, Time. R. H. 



Abscissa, Practice Periods. 
, L. H. . 



Ordi- 



to be a rule, but rather that individual characteristics, with 
perhaps environmental or physiological factors, cause such 
exceptions in both sexes. 
(2) Index of Fatigue. 

The difference in daily averages of time required for 
first and second fifty taps indicates the loss in rate from 
fatigue. These differences are given in Table I under Diff. 

We computed the fatigue index by taking the percentage 
of this difference to the efficiency for the first fifty taps, ob- 
taining the following results. 

Fatigue-index for boys, R. H. 19% ; girls 20%. 

Fatigue-index for boys, L. H. 22% ; girls 20%. 

These are lower than that of 24% found by Gilbert for 
children eight years old, showing perhaps an increased 
immunity to fatigue through practice. 

We also computed the average daily deviations of the 
fatigue loss, finding : 



RATE OF VOLUNTARY MOVEMENTS 2'J 

A. D. for R. H. Boys 0.5771 ; Girls 0.354. 

A. D. for L. H. Boys 0.8442 ; Girls 0.5462. 

From these we obtain the probable error^ of the differ- 
ence between the averages for boys and girls. 

P. E. for R. H. 0.233 ; L. H. 0.345. 

The difference of 0.003 for right hand is only 0.028 times 
its probable error; that of 0.387 for left hand, 1.12 times 
its probable error. We can not conclude the slight differ- 
ences are significant of sex differences in loss from fatigue. 
The difference for left hands is of more significance and 
may be accounted for by the decided left-handedness of 
two of the girls. 

The greater fatigue index for boys with the left hand 
is characteristic of a normal distribution. In case of girls 
the equality in percentages for both hands is not surprising, 
because of the individual variations already noted. 

There appears to be no definite connection between rate 
and fatigue loss within the limits of this experiment. The 
boy and girl making best speed for one hundred taps had 
a relatively low fatigue index. Other subjects were 
irregularly arranged as to rank in rate and in loss by 
fatigue. In the first few trials, there is a tendency to 
lessen speed at the onset of fatigue, but to increase energy 
by pounding on plate. Practice tends to eliminate the keen 
sensations of fatigue and the increased force in striking. 

In order to study more carefully the relation between 
rate and fatigue, as objectively shown by decrease for last 
fifty taps, two girls and one boy were given tests of longer 
duration in the laboratory. A series of trials, ranging from 
three to five, were given during one laboratory period, with 
intervals of ten minutes between trials. A trial consisted 

1 P. E. of mean was obtained by following formula : P. E.m 
0.8453 
= A. D., where n is total number of individual measure- 

Vn — I 
ments, and A. D. is average deviation. 

P. E. of the difference between two means, M^ and Mj, was found 

as follows : P. E.d = ypTE.ifi^ — P- E.iro2 . 



28 



MOTOR ABILITIES OF CHILDREN 



of one hundred taps with right hand ; after a minute's rest, 
one hundred taps with left hand. These children came to 
the laboratory once a month during five months. 

Averages for individuals are given in following table. 









TABLE III 












Age 


R. H. 


L. H. 




(I) 


(=) 


T. 


D. 


(I) 


(2) 


T. 


D. 


W. girl 

X. girl 

Y. boy 


10 

8 
8 


8.98 
8.17 
9-03 


10.31 
9.00 
947 


19.29 
17.17 
18.51 


1-33 
0.83 
0.44 


9.71 
7.71 
8.63 


11.60 

8.51 

10.41 


20.77 
16.22 
19.09 


1.88 

.80 

1-73 



(i) and (2) columns have number of seconds required 
for first and second fifty taps. T. is total of (i) and (2). 
D. is difference between (i) and (2). 

There is again no direct correlation of rate with fatigue. 
Greater fatigue occurs when rate is slowest, save in case 
of boy's right hand. He preferred use of left hand but 
development of right-hand ability had almost resulted in 
ambidexterity, as the slight difference between the two 
records shows. 
(3) Left-handedness. 

The individual records give convincing evidence that the 
tapping test is a most reliable one for securing an index 
of left-handedness. The two girls of the regular group 
who were left-handed were consistently so throughout the 
series. There were a few trials in which scores for hands 
were equal. This was also true for the right-handed 
group. One exceptional case was X, whose record is given 
in Table III. Her first day's records showed a superiority 
of one second in rate for right hand. Her left hand was 
decidedly superior in later records and in final average. 

We computed the percentage of left-hand to right-hand 
efficiency, by finding excess of time required for left- 
hand as compared with rate for right-hand. This gives for 
boys an indexof 79.2% ;, for girls, 78.8%. This is somewhat 
surprising when we have two left-handed girls in group 



RATE OF VOLUNTARY MOVEMENTS 



29 



and no boys that are left-handed. We beheve the explana- 
tion is found in the records of girls I and H, that have been 
given, whose left hands were exceptionally poor, far ex- 
ceeding in inferiority the records of the right hands of the 
two girls who were left-handed. 
(4) Sex Differences. 

In Table IV the individual averages for boys and girls 
are given. The capital letters represent individual girls, 
the small letters individual boys, (i) and (2) refer to 
first and second fifty taps. Numbers in columns are time in 
seconds. A. D. is average deviation. 

TABLE IV 



Boys 


Girls 




R. H. 


L. H. 




R. H. 


L. H. 




(i) 


(2) 


(i) 


(2) 


(I) 


(2) 


(X) 


(2) 


a 


12.16 


13-57 


12.50 


16.48 


A 


8.88 


10.54 


11.04 


13-98 


b 


10.17 


12.30 


12.28 


14.28 


B 


9-36 


1 1. 15 


10.86 


13-89 


c 


11.64 


13-63 


12.69 


15-34 


C 


9.81 


11.20 


11-54 


15-43 


d 


10. II 


11.48 


12.10 


13.66 


D 


11-33 


13-33 


10.18 


12.46 


e 


10.12 


12.88 


13-45 


16.76 


E 


11.62 


13.92 


11.65 


13.70 


f 


10.16 


12.06 


13-13 


16.86 


F 


8.48 


10.20 


10.26 


11.86 












G 


11.42 


13-73 


13.40 


16.40 












H 


11.26 


13.62 


15-56 


17.81 












I 


9-75 


12.50 


15-37 


18.40 












.1 


10.08 


10.60 


12.60 


15-13 












K 


10.24 


12.40 


12.33 


15-27 












L 


10.35 


12.80 


11.46 


13-63 












M 


8-74 


11.30 


12.04 


13.68 


Av. 


10.72 


12.65 


12.67 


15-56 




10. xo 


12.10 


12.17 


14-74 


A. D. 


0.782 


0.706 


0.415 


1. 13 




0.864 


1. 169 


1-368 


i-53« 


Total Av.. . 2'K.'\7 


28.25 
27-99 




22 20 


26.91 

25-37 


Median 22.73 




22.25 



The time required by girls for one hundred taps was 
1. 179 seconds less for right hand; 1.334 seconds less for 
left hand than that required by boys. In each case the 
left hand range was greater than the right and the range 
of girls exceeds that of the boys. 

To correct the error due to unequal distribution of sexes 
and to small number tested, the probable error of the dif- 



30 MOTOR ABILITIES OF CHILDREN 

ference between the averages of boys and girls was found. 
P. E. of difference for R. H. 0.365 
P. E. of difference for L. H. 0.447 
Since the difference for right hand is 3.23 times its P. E., 
for left hand 3.98 times its P. E., these differences must 
be a valid indication of sex differentiation. 

To summarize the results from the tapping test for sub- 
jects studied, we may note: 

That there is marked improvement due to practice with 
great irregularity in early trials. 

That the initial trial, or average of less than five trials, 
does not give a true indication of actual abihty in rate of 
movement. 

That the loss from fatigue is not directly correlated with 
rate, but varies irregularly ; is not a distinct sex character- 
istic ; and the index is greater for use of hand not preferred. 

That there is a distinct sex differentiation in ability in 
tapping test in favor of girls. 

That the index of right-handedness obtained, in accord- 
ance with the results of other investigators, shows more 
pronounced efficiency in use of preferred hand during child- 
hood than in adult life. ' 



V. STEADINESS OF MOTOR CONTROL 
I. Apparatus 

Measurement of involuntary movements was made by 
method similar to that described in Whipple's (24) Manual, 
Test 13. The brass plate had a series of holes arranged in 
two rows. Beginning with the one in the lower left-hand 
corner, the diameters of the holes were respectively 32, 28, 
24, 20, 16, 12, 10, 9, 8, 7 and 6 sixty-fourths of an inch. 
The first five, which were in lower row, were the only ones 
reached within the limits of this experiment. The stylus 
consisted of a metallic needle one-sixteenth of an inch in di- 
ameter and one and five-eighths of an inch long, in a wooden 
cylindrical handle three-eighths of an inch in diameter and 
four inches long. The weight of stylus was twelve and a 
half grams. Plate, stylus, and a telephone receiver were 
wired in series with battery so that contact between needle 
and plate caused a click in the receiver. Graphic record 
was not made, and we recognize the source of error in the 
counting of strokes made by sounder when tested. The 
very short, rapid contacts produced such noticeable clicks, 
we believe the probability of errors in correct counting to 
be so small as not to cause significant differences in results. 
A stop-watch was used to time the trials. 

2. Method of Conducting Test 

Before the test was given each child was allowed to put 
the receiver to his ear and with stylus in other hand make 
the contact. Then it was explained to him that he was 
to make as few contacts as possible during his test. He 
stood at a distance from the table a little greater than the 
length of the arm from the elbow and with shoulder of arm 
used in front of plate. Hand and arm were free from all 

31 



32 



MOTOR ABILITIES OF CHILDREN 



support or contact with body. Plate was set flush with 
edge of table and adjusted at an angle such that the stylus 
was held perpendicular to plane of plate. Each subject 
was allowed three seconds to get needle in position before 
watch was started. Time for trial was fifteen seconds. 
Only two children were in room with experimenter at same 
time. Right hand was tested first in each hole, beginning 
with the largest, until the number of contacts in one hole 
equalled or exceeded twelve. Between tests for each hole 
fifteen seconds were given for resting arm. The left hand 
was then tested in similar manner. 

3. Subjects 

The subjects were same as those in tapping test. The 
first steadiness test was given before the practice series in 
tapping, the second afterward. Records are for seventeen 
girls and eight boys. 

4. Computation of Results 

The numbers of contacts made in each hole are averaged, 
separately for sexes, and the total number of contacts for 
the five holes is also given. Taking hole three as the 
one most satisfactorily testing the steadiness of these sub- 
jects, the average deviation of individuals from the group 
average was computed for right hand in hole three. The 
probable error of the difference between these averages for 
sexes was obtained, as a measure of the reliability of the 
sex difference. 

5. Results 

In Table V the records from both tests, averaged for 
sexes, are shown for the five holes. 

TABLE V 

Total 



Boys 
Girls 
Boys 
Girls 





I 


2 


3 


4 


5 


R.H. 
R. H. 
L.H. 
L.H. 


1.06 
0.94 
3.12 
3-25 


2, 
1.47 

4-43 
4.82 


5-12 

3-35 
5.81 
7-37 


6.43 
4.64 

8.95 
10.18 


10.75 
10.09 
10.5 
I4.I 



25-36 
20.49 
32.81 

39-72 



STEADINESS OF MOTOR CONTROL 33 

In this test it is generally agreed that elimination of cer- 
tain factors, as distraction and moving of body, is of more 
importance than the repetition of tests. Children respond 
to the slightest external stimulus. Under seemingly most 
desirable conditions for experimentation one boy made a 
very poor record, which was somewhat explained by his 
statement later that his father owned an engine for cutting 
wood. A slight buzzing sound that came through the 
window was found to be from a wood yard near the school. 

The trick in method, control of respiration, is not de- 
veloped by the children, but the disturbance in respiration 
is very evident. 

The movements with some are slight but almost con- 
tinuous. In others there are larger movements more spas- 
modic. These also vary as to form. A sidewise or 
irregularly circular motion prevails with some, while in 
others there is a tendency to go forward, then back. One 
girl would sometimes let needle of stylus go almost its 
entire length through a hole and back again without a con- 
tact. This was with right hand. The same form of move- 
ment occurred with left hand, but was not so well con- 
trolled, 
(i) Practice Effects. 

When the averages of contacts made in each hole are 
considered separately for the two tests, both sexes show 
slight improvement with both hands in second test. This 
was not true of all individual records or for both hands in 
same individual. The boy who made best record of entire 
group in both tests made best score in first test. 
(2) Sex Differences. 

Girls are superior with right hand, boys with left. The 
exceedingly poor coordination with left hand by two girls 
may partially explain the latter result. Subject I again 
showed the same distance between her hands. In hole two, 
with right hand, she made in first and second test respec- 
tively six and two contacts ; with left hand, sixteen and 
seventeen contacts. 



34 



MOTOR ABILITIES OF CHILDREN 



Taking records for right hand in hole three we find an 
average deviation for girls of 2.53 contacts ; for boys, 4.45 
contacts. The probable error of the difference 1.77 be- 
tween their averages is 0.553. The difference is 3.2 times 




4 s 

Fig. 5. Steadiness Test. Abscissa, Number of Hole. Ordinate, 

Averaged Number of Contacts. Boys, R. H. , L. H. — . 

Girls, R. H. , L. H. . 

its P. E. and indicates superiority of the girls with right 

hand. 

(3) Index of Right-handedness. 

The results for individuals vary from test to test with 
hole and with hand used. Shifts in superiority from right 
to left hand and vice versa are noticeable. Of the two left- 
handed girls as determined by tapping test, only one was 
left-handed in steadiness test. For boys the index of right- 
handedness is 7y% ; for girls, 51%. This shows clearly the 
inefficiency of left hands of certain individuals in the group 
of girls. 

The difficulty of control in this test and the covering up 
of actual measurement by averages for groups that may 
include extreme departures from the mode invalidate many 
results. If a number sufficiently large could be selected, by 
elimination of the extremes, a norm might be established. 
It is to be questioned if results of Woolley and Fischer (23) 
from tests given a year apart and at the time children four- 



STEADINESS OF MOTOR CONTROL 35 

teen and fifteen years old came to apply for working cer- 
tificates, justify their vocational diagnosis, that for "posi- 
tions requiring strength or mere rapidity of motion 
(particularly at fifteen years) boys would be better. For 
those requiring steadiness or fine motor control, girls would 
be better." 



VL REACTION TIMES 
I. Apparatus 

In measuring the reaction time of children to visual 
stimulus, we believed an object of interest to a child would 
be a better stimulus than mere geometrical designs such as 
are frequently used. Transfer pictures of a dog and bird 
were put on the milk glass plate in the screen used for 
displaying the stimulus. By means of an electric bulb just 
behind the plate and a slide with a rectangular opening, 
either object desired could be shown. The connections 
between operating keys, the D'Arsonval chronoscope, and 
light behind screen were such that when the experimenter 
pressed the keys the picture appeared and simultaneously 
the hand started, and when child squeezed a bulb the hand 
stopped. 

2, Method of Conducting Test 

The subject sat within a shaded compartment, just in 
front of screen, with arm in comfortable position, and hold- 
ing a rubber bulb in right hand. Only a black curtain 
separated the subject from the experimenter, so that the 
passage of air when bulb was squeezed was sometimes 
heard when subject responded too soon. Caution was given 
that the noises incident to giving or changing stimulus were 
not to be heeded as significant in any way. To prevent re- 
sponse to noises, similar ones were given each time. The 
slide was pushed back and forth whether picture was 
changed or not. Time between changing of slide and giv- 
ing of stimulus was also varied to prevent a rhythmical 
response. We believe, however, that the elimination of all 
other stimuli than the visual was not so successful but that 
occasional errors entered. When the time was varied be- 
tween click and appearance of picture, reaction was often 

36 



REACTION TIMES 37 

made too soon. Some very short reactions may have been 
due to this anticipatory response. 

Simple reaction times were first obtained by giving 
preferred object, bird to three girls, dog to one girl and one 
boy. After one hundred simple reactions were made, the 
discriminative reactions were begun. In the latter case, 
the subject was to respond to the object as previously given, 
but not to respond when the other appeared. Finally 
another one hundred simple reactions were made. 

Some preliminary tests were given in order to find out 
the number of reactions that could be made during a sitting 
without too great fatigue and the number of sittings de- 
sirable during a laboratory period. The boy Y had been 
given one hundred simple reactions in the spring of 191 5, 
responding to five circular dots. He was given a few more 
with the dog to note any difference that might occur be- 
cause of stimulus. His interest was so keen in his first 
work at the laboratory that no marked difference appears 
and his average is made from the total number of simple 
reactions. 

During the early preliminary trials bird or dog was chosen 
at random and listed. For the real tests, order of presenta- 
tion was chosen by use of deck of cards. The children 
held themselves under rather high tension in anticipation 
of stimulus. This was not maintained to so great a degree 
during later and shorter sittings. During first simple re- 
actions, twenty-five were made at a sitting. It was found 
best to give only ten presentations at one sitting, and this 
procedure was adopted for the discrimination reactions and 
for the second series of simple reactions. By giving a rest 
of ten minutes between sittings it was easy to get twenty- 
five reactions, or to give fifty presentations, during a period. 
This work was begun the latter part of Odober, 191 5, and 
continued through March, 1916, with intervals of two to 
four weeks between laboratory periods. 



38 



MOTOR ABILITIES OF CHILDREN 



3. Subjects 

Four girls and one boy, children of professors of the 
University, were used in the reaction time experiment. 
They ranged in age from four to ten years. The four- 
year-old made only simple reactions. 

They were evidently pleased to come to the laboratory 
and seemed to enjoy various tests undertaken. The reac- 
tions were interesting at first but the monotony necessarily 
involved proved irksome to the children. Only by short 
sittings and because of the pleasure of getting to the labora- 
tory were they sufficiently stimulated to complete the tests. 

4. Treatment of Data 

Averages were obtained for the total number of reac- 
tions. For some subjects this number varied slightly from 
the one hundred planned, but we deemed it advisable to 
average unquestioned scores just as they were. Number 
of reactions, maximal and minimal reaction time, and num- 
ber of errors in discrimination reactions are also listed. 
The reaction times are expressed in thousandths of a second, 
or (T. 

5. Results 

Tables VI and VII give our resultant values from aver- 
ages for individuals and also show Gilbert's results. His 
averages for the ages are based on median value of ten 
reactions from fifty of each sex, the discrimination reaction 
preceding the simple. 

TABLE VI 
Simple Reaction Times 





Sex 


Age 


Preceding Discrimination 


After Discrimination 






Av. 








Av. 






Gil- 








No. of 


Time 


Max. 


Min. 


No. of 




Max. 


Min. 


bert's 








Trials 


in <r 


Time 


Time 


Trials 


in <r 


Time 


Time 


Av. in <r 


z 


girl 


4 


105 


428 


1050 


100 












V 


girl 


6 


100 


415 


1000 


100 


100 


239 


650 


40 


295 


X 


girl 


8 


132 


315 


63B 


77 


100 


220 


750 


30 


260 


Y 


boy 


8 


160 


263 


600 


160 


100 


130 


310 


20 


245 


w 


girl 


10 


102 


250 


640 


no 


100 


127 


350 


20 


225 



REACTION TIMES 



39 



TABLE VII 
Discrimination Reactions 









No. of 


Av. Time 


Max. 


Min. 


No. of 


Gilbert's 


Indiv. 


Sex 


Age 


Trials 


in <T 


Time 


Time 


Errors 


Av, in <T 


V 


girl 


6 


77 


404 


II50 


60 


11 


510 


X 


girl 


8 


140 


324 


1300 


80 


13 


475 


Y 


boy 


8 


100 


253 


850 


40 


8 


480 


w 


girl 


ID 


84 


187 


650 


20 


8 


415 



The simple reaction time for trials preceding the dis- 
crimination are longer even than the discrimination reaction 
times, with the exception of the eight-year-old girl, and 
much longer than those found by Gilbert for subjects of 
same age. These latter were made after his discrimination 
reactions, but his trials were so few the effect of practice 
does not sufficiently explain the difference. His results are 
the averages for a large number of subjects and based on 
the median value for a subject, so not actually comparable 
with the individual records we have listed. 

It was to be expected that the greater practice would 
make the simple reaction times for the last series shorter 
than the first, but it was surprising to note that in two cases 
they are much shorter than the time Gilbert found for the 
subjects seventeen years old, boys 147; girls 163. This is 
representative of the normal simple reaction time of adults 
found by other investigators. 

x\s a child more fully understood just what was expected 
of her, and also realized that other children were doing the 
same thing, a spirit of competition developed. This was not 
purposely encouraged but was a natural development evi- 
denced by such remarks as, " Do I do as well as the others ? " 
and, " Oh, I tried not to go too soon." This latter remark 
also indicates the anticipatory state in which the child was 
so ready to respond that the reaction would often have been 
made whether the stimulus appeared or not. The objective 
evidence of this was given when the time of giving stimulus 
was varied and reactions were made too soon. 

The discrimination times reported by Gilbert are rather 



40 MOTOR ABILITIES OF CHILDREN 

long, but one who has noted the lengthened period of ad- 
justment necessary for young children would expect such 
from the few trials. The records we have obtained com- 
pare most favorably with those for adults. Gilbert's aver- 
age in discrimination for those seventeen years old is for 
boys 305; for girls 315. The number of errors we found 
was not excessive. Premature responses were not so fre- 
quent as in the simple reactions. The inhibition that pre- 
vented response to wrong stimulus seems carried over into 
inhibition of premature responses. The extremely short 
minimal times seem to be partly due to chance. Subject W 
once remarked, "I'm so glad it was a bird. I believe I 
would have pressed if it had been a dog." 

While for these few subjects there is increasingly 
shortened reaction with increasing age, the averages ap- 
proximate much more closely those for adults than results 
in other motor tests have done. Usually the adult records 
are based on fewer trials and perhaps upon more fatiguing 
periods of experimentation than were practical for the 
children. A most interesting problem would be a prolonged 
comparative study of reaction times for different ages, de- 
termined under same conditions. 



VII. ACCURACY OF MOVEMENT 
I. Apparatus 

A wooden board 26 by 37 inches was painted black and 
sanded to prevent sliding of bags. On this board four 
concentric circles were described in white paint. The cen- 
tral circle had a diameter of six inches; the others, re- 
spectively, twelve, eighteen, and twenty-four inches. The 
board was divided into halves, both horizontally and ver- 
tically, by two straight lines intersecting in the center of 
the system of circles. There was an adjustable support, 
so the board could be inclined at such an angle that the bags 
would fall perpendicularly upon it. The bags were circular, 
three and a half inches in diameter, filled with rice, and 
weighed fifty-four grams. 

2. Method of Conducting Test 

The board was placed upon the floor against a wall. 
Each subject stood at a distance of six feet from the lower 
edge of board, and in such position that the arm used was 
in line with the vertical line upon board. His aim was the 
center of the circles where the straight lines intersected. 
Freedom in manner of throwing was given as to tossing or 
overhand throw. Only occasionally was the latter used. 
Tossing the bag proved to be a more accurate method and 
was adopted by all. 

Groups of twelve children, six boys and six girls, will be 
designated according to intervals between practice. The 
five-days-a-week group were given ten throws with each 
hand, the right preceding, on each school day for the first 
three weeks in December, between eleven and twelve 
o'clock. 

The Tuesday-and-Thursday group were practiced from 

41 



42 MOTOR ABILITIES OF CHILDREN 

ten to eleven o'clock on the days mentioned until the total 
number of throws equalled that of the first group. 

The once-a-week group were given twenty throws with 
each hand on Thursdays between nine and ten o'clock. 

The once-in-two-weeks group had ten throws with each 
hand on Tuesdays from nine to ten o'clock. During the 
later practice periods these were given fifteen throws with 
each hand. They were somewhat younger than the once-a- 
week group and because of fatigue effects it was thought 
best to give only ten throws at the beginning, but later the 
fifteen throws seemed desirable. 

The Christmas holidays made an interval of two weeks 
without practice for all the groups save the first. In each 
case periods were arranged so that one hundred and forty 
throws were made with each hand, the right preceding. If 
a child was absent more than three times, he was eliminated. 

3. Sources of Error 

Since the line of motion varied from throw to throw, 
the bag did not fall perpendicularly upon the board each 
time. When it did, it remained where it first touched. 
With varying trajectories given by the tosser, the bag met 
the board at varying angles. This, together with force of 
throw, caused the bag to skid or to turn over at times. By 
noting exact difference this made in score of several indi- 
viduals during a number of practice periods, it was found 
that the error was never greater than one on a single throw 
or three for a practice period with one hand. There was 
rarely a change in score unless bag fell in line with center 
and it is evident that here the errors on the upper side tend 
to counter-balance those on the lower side. 

An attempt was then made to ascertain any constancy as 
to portion of board struck by individual thrower. There 
was no regularity as to direction of error for the subjects 
who were studied for this purpose. We believe the scores 
are representative, the slight residue of errors from these 
sources being as probable for one subject as another. 



accuracy of movement 43 

4. Method of Scoring and Computation of Results 

If the bag fell within the inner circle it touched the 
central point and the score recorded was four; within the 
next circle, three; the next, two; the outer circle, one. If 
partly in one, then the score was recorded for that circle 
within which it clearly lay. Anywhere outside the outer 
circle was scored zero. The total individual score for a 
practice period was divided by the number of throws made 
and the quotient recorded. The records for subjects within 
a group were averaged for each practice period. The curves 
were drawn according to these averages. Final averages 
for the sexes were obtained for group comparisons. The 
average daily deviations from the final average and the 
probable errors were also calculated as a measure of relia- 
bility of score. 

5. Results 

The tables VIII, IX, X, and XI give the average per- 
formance of each group, a statement of the average devia- 
tion, and the probable error of the difference between the 
averages for the sexes. 

5-Day s-a-Week Group 

The average age of this group was six years, seven months 
for girls, within a range of one year, one month ; for boys, 
six years, two months, ten days, within a range of five 
months. Records given are for five girls and five boys. 

While the individual differences in efficiency are largely 
eliminated in the consideration of the averages for the 
groups as a whole, they do enter into the computation of 
rate and amount of improvement for a particular group in 
a way that causes a defect so far as practice effects are 
concerned. The majority in a group might show slight im- 
provement on one day, yet if the best performers of the 
preceding day chanced to make unusually poor throws, the 
final average for that day would be lower. 

The experiments were necessarily extended throughout 



44 



MOTOR ABILITIES OF CHILDREN 



TABLE VIII 

Showing the Daily Averages for the Five-Days-a-Week Group 



Day 


Girls 


Boys 


R. H. 


L. H. 


R. H. 


L. H. 


I 

2 
3 

4 
5 
6 

7 
8 

9 

lO 

II 

12 

13 

14 


1-5 
1-9 

1-725 
2.075 

1.6 

1-4 

1-833 

1-7 

1-9 

1.6 

1.56 
1.72 

1-44 
1.4 


1-475 
0.98 

1-475 
1-25 
1.2 
1.2 

1-433 

1.2 

1.6 

1.4 

1.32 

1.66 

1-34 

I-I5 


2.033 

1-633 

1-9 

1-633 

1.62 

1.66 

1-383 
1.48 

1-54 
1-55 
1.283 

1-35 
1. 416 

1-54 


1-3 
1-3 

1.2 

I-I5 

1.06 

0.98 

1. 116 

1.38 

1.06 

I-I33 
1.083 
1. 00 

1-25 

1.26 


Total 

Av 


23-353 
1.668 
0.168 


18.683 

1-334 
0.148 


22.021 

1-573 
0.148 


16.272 
I 62 


A. D 


0.102 



Difference between averages for R. H. 0.095 

L. H. 0.172 
Probable error of R. H. difference 0.0945 
L. H. difference 0.0759 

such a long period absences were unavoidable. We could 
not eliminate all who were absent for any period because it 
reduced the groups too much for study. The absence of a 
thrower who was above the average ability reduced the 
score for that day as compared with the preceding practice 
period. 

In many individuals there was a continued but irregular 
improvement. This was shown especially by those who 
were poor in coordination at the beginning, frequently fail- 
ing to hit the board. 

The curve for the right hand of girls is similar to the 
general learning curve, with more irregular gains during 
the first five days. On the sixth and last day the records 
are inferior to that for first day. With the left hand there 
are fluctuations of considerable magnitude. On three days 
later in the series records equalled or excelled that of the 



ACCURACY OF MOVEMENT 



45 



first day, but elsewhere no improvement was shown and 
the final average is less than the score for first day. 

The initial record for boys was superior to any later 
record and to final average for boys' right hand. With 
left hand there were only three days in which improvement 




Abscissa, Practice Periods. 
, L. H. . Girls, 



Fig. 6. Five-Days-a-Week Group. 
Ordinate, Daily Score. Boys, R. H. 
R. H. , L. H. . 



was shown over the first and the final average was inferior. 
There is a possibility that in this group the excitement 
and overstrain often produced by preparations for Christ- 
mas caused the decrease in efficiency during the trials for 
the last week. 

2-Day s-a-Week Group 

The average age for this group was six years, five months, 
seven days for girls ; six years, two months, five days for 
boys. Five boys and four girls were included in final 
records. 

The curve for girls shows gradual gain with varying 
fluctuations. Again the boys show almost maximal effi- 
ciency on the first day. With the right hand there is 
gradual improvement through the fourth day with an irreg- 



46 



MOTOR ABILITIES OF CHILDREN 



TABLE IX 
Showing the Daily Averages of the Two-Days-a-Week Group. 





Tuesdays and Thursdays 






Girls 


Boys 














R. H. 


L. H. 


R. H. 


L.H. 


I 


1-275 


0-95 


I.616 


1.483 


2 


1.36 


1.08 


1-683 


1.05 


3 


1-25 


1.25 


1-733 


1. 216 


4 


1.70 


1-275 


1-75 


1.066 


5 


1.50 


1. 10 


1.466 


1.05 


6 


1.38 


1. 16 


1-533 


1.066 


7 


1-275 


1.30 


1.586 


0.966 


8 


1-35 


1.30 


1.58 


1. 16 


9 


1-325 


1. 00 


1.46 


1. 18 


ID 


1.30 


1.30 


1.48 


1. 16 


II 


1.90 


1. 125 


1.30 


1. 10 


12 


1.24 


1. 180 


1.60 


1. 10 


13 


1.65 


1.625 


1.616 


1. 116 


14 


1-333 


1-033 


1-683 


1-25 


15 


1.426 


1-475 


1.366 


1.483 


Total 


21.263 


18.153 


23-432 


17.446 


Av 


1.417 
0.144 


I 210 


1.562 
0.102 


1. 163 
0.106 


A. D 


0.134 



Difference between averages for R. H. 0.145 

L. H. 0.047 
Probable error of R. H. diflference 0.0745 
L. H. difference 0.0721 




Fig. 7. Two-Days-a-Week Group. Abscissa, Practice Periods. 

Ordinate, Daily Score. Boys, R. H. , L. H. . Girls, 

R. H. . L. H. . 



ACCURACY OF MOVEMENT 



47 



ular decline until the thirteenth day, when the score equals 
that of initial records. The average results for both hands 
are less than the initial scores. 

There was seemingly no lack of interest on the part of 
the boys but there is an indication that they did not put 
forth their best efforts. There was sometimes a tendency 
to attempt a fancy throw. 



Once-a-Week Group 

The average age of this group was seven years, four 
months, eighteen days for girls ; seven years, eight months, 
five days for boys. The records of six girls and six boys 
are reported. 

TABLE X 

Showing Daily Averages for Once-a-Week Group, Having 
Twenty Throws with Each Hand in a Practice Period 





Girls 


Boys 


Day 


R. H. 


L.H. 


R. H. 


L. H. 


I 
2 
3 

4 
5 
6 

7 


1.483 

1-333 
1-366 

1-875 
1-537 
1.36 
1.61 


1-233 
1. 216 

1-275 
1.508 

1-325 
1.06 

1-43 


1.683 
1-36 

1-54 
1-54 
1.608 

I-591 

1-558 


I.6I6 

1-73 
1-425 

1.42 

1-375 
1.616 

1-45 


Total 

Av 


10.564 

1-509 
0.141 


9-047 
1.292 

O.II 


10.881 

1-554 
0.063 


10.632 
1-519 
0.115 


A. D 



Difference between averages for R. H. 0.045 

L. H. 0.227 
Probable error of R. H. difference 0.0574 
L. H. difference 0.0612 

A substantial but somewhat irregular improvement is 
shown by the girls. The boys show the high initial efficiency 
that has characterized the boys of the other groups, with but 
slight evidence of improvement shown either by daily 
averages or final average results. 



48 



MOTOR ABILITIES OF CHILDREN 



Once-in-Two-W eeks Group 

For the girls of this group the average age was seven 
years, one month, within a range of one year, one month; 




I 2 3 4 5 & 7 

Fig. 8. Once-a-Week Group. Abscissa, Practice Periods. Ordi- 
nate, Daily Score. Boys, R. H. , L. H. . Girls, R. H. 



L. H. . 



for the boys the average age was six years, three months, 
fifteen days, with a range of nine months. The records are 
given for six girls and five boys. 

With right hand there is a decrease in efficiency on second 
day for boys, on second, third and fourth days for girls. 
Then a gradual rise in curve shows slow but fairly regular 
improvement. 

The left hands show much more instability. The average 
result for girls with left hand was less than score for first 
day and the boys show very slight improvement. In this 
group there was no subject who gave evidence of any desire 
to use left hand, but rather a marked preference for right. 
( I ) Practice Effects. 

The indications are that the limit of improvement has not 
been reached. The rate is so lacking in uniformity and 
varies so considerably for different groups that it is difficult 



ACCURACY OF MOVEMENT 



49 



TABLE XI 
Showing Daily Averages for Once-in-Two-Weeks Group 





Girls 


Boys 




R. H. 


L. H. 


R. H. 


L. H. 


I 

2 

3 
4 
5 
6 

7 
8 

9 

10 

II 


1. 516 

1433 

1.33 

1.4 

1.86 

1.744 

1.766 

1.84 

1.84 

1.7 

1-73 


1-35 

1.32 
1. 216 
I. 

1.26 

1-255 
I -033 
1.44 
1.26 
1. 188 
1.366 


1.4 
1. 12 
1.64 
1-7 

1.6 

1-573 
1.72 

1-7 
1-453 
1.706 
1.6 


I.I 

0.76 

0.8 

1.26 

0.975 

1-253 

1-44 

1-25 

1.2 

1-253 
1.266 


Total 

Av 


18.159 
1.65 
0.168 


13.688 
1.244 
0.098 


17.212 
1.564 
0.131 


12.557 
1. 141 
0.28 


A. D 



Difference between averages for R. H. 0.086 

L. H. 0.103 
Probable error of diiference for R. H. 0.084 

L. H. 0.124 

to get any satisfactory indication of acceleration or retarda- 
tion of improvement. The irregularities may be accounted 




Fig. 9. Once-in-Two-Weeks Group. Abscissa, Practice Periods. 

Ordinate, Daily Score. Boys, R. H. , L. H. . Girls, 

R. H. , L. H. . 

4 



50 



MOTOR ABILITIES OF CHILDREN 



for in part by differences in initial ability, in native capacity 
to improve, and in cooperation 'of subject. 

The amount of improvement as measured by comparison 
of first day's score with final average is more clearly shown 
in the following tables. The percentage columns represent 
the percentage of initial efficiency which the final average is. 

TABLE XII 

Showing the Relation between the Initial Scores and Final 
Averages for Right Hands of All Groups 





Girls 


Boys 


Group 


ISt 

Day 


Av. 


% of Im- 
provement 


ISt 

Day 


Av. 


% of Im- 
provement 


5-DayS-a-Week 


1-5 
1-275 
1.483 
1. 516 


1.668 
1.417 
1-509 
1.65 


II.2 
II. I 

1-75 

8.83 


2.033 
I.616 

1-683 
1.4 


1-573 
1.562 

1.554 
1.564 


— 22.6 


2-Days-a-Week 


- 3-34 

- 7.66 
II. 7 


i-Day-a-Week 


l-Day-In-2-Weeks 



TABLE XIII 

Showing the Relation between the Initial Scores and Final 
Averages for Left Hands of All Groups 





Girls 


Boys 


Group 


ISt 

Day 


Av. 


% of Im- 
provement 


ISt 

Day 


Av. 


% of Im- 
provement 


5-Days-a-Week 


1-475 

0.95 

1-233 

1-35 


1-334 
1.21 
1.292 
1.244 


- 9-4 
27-3 
4-78 
7-85 


1-3 
1.483 
I.616 
I.I 


1.62 
1. 163 

I-519 
1. 141 


— 10.6 


2-Days-a-Week 


-21.3 
- 6 


i-Day-a-Week 


i-Day-in-2-Weeks 


3-72 



The negative improvement shown in boys' records in- 
validates somewhat conclusions for groups as a whole. The 
once-in-two-weeks group shows greater improvement in 
consideration of entire group. The girls in the two-days- 
a-week group have less initial ability, hence greater percent- 
age of improvement, if both hands are considered. 

From the percentages of improvement given for girls, it 
is evident that the short and frequent practice periods are 
more valuable. The group having greatest number of 
throws during a practice period with only one period a week 
shows very little improvement. The co-operation of the 



ACCURACY OF MOVEMENT 5I 

subject is so closely related to the improvement, for the de- 
termination of the most economical distribution of the prac- 
tice periods, it seems necessary to stimulate the subject suffi- 
ciently for complete response to the task. Unless this can 
be accomplished in frequent practice periods, then longer 
intervals are more desirable. 

(2) Index of Right-handedness. 

By computing the percentage of efficiency of the left hand 
to the right hand we obtain for the various groups the fol- 
lowing indices: 

Boys Girls 

S-Days-a-Week 73 per cent. 79 per cent. 

2-Days-a-Week; 74 per cent. 85 per cent. 

i-Day-a-Week 96 per cent. 85 per cent, 

i-Day-in-2-Weeks 73 per cent. 75 per cent. 

In the Once-a-week group the large percentage for boys 
is due, doubtless, to the consistent superiority of left hand 
in one subject. In same group two girls were slightly 
superior with left hand in final average. In Two-days-a- 
week group the left hand of one girl excelled her right hand 
in the majority of throws. From 73% to 80% efficiency 
with left hand is characteristic of groups having no left- 
handed subjects. This can not be accepted as an absolute 
index since right hand preceding left may condition it to 
some extent. 

(3) Sex Differences. 

According to the final averages the girls are superior with 
both hands in the Five-days-a-week and Once-in-two-weeks 
groups and for left hand in Two-days-a-week group. Im 
other cases the boys excel. 

The probable errors show that the diflferences between? 
the averages for the sexes are insignificant except for left 
hand of Five-days-a-week and Once-a-week groups. In the 
former case the difference of 0.172 in favor of girls is 2.26 
times its P. E. There was one girl in this group who 
showed slight superiority with left hand. 

In the second case the difference of 0.227 in favor of boys 
is 3.7 times its P. E. One of these boys was decidedly left- 



52 MOTOR ABILITIES OF CHILDREN 

handed. Aside from these differences that the particular 
cases might explain there is no distinct sex differentiation 
evidenced by average results. 

There is a noticeable sex difference in the course of im- 
provement from day to day. In all groups of boys except 
the Once-in-two-weeks group, the final average was less 
than the initial score and the maximal score was made either 
on first day or in early trials. The girls follow more closely 
the usual course in learning and with the exception of two 
left-hand averages, make better final averages than initial 
records. Maximal efficiency is not attained until fourth day 
or often much later in the series. 

This suggests continued co-operation on part of girls 
throughout the series, while the boys failed to respond with 
the same interest during later trials. This is most notice- 
able in the Five-days-a-week group. 

The curve of boys who practiced only once in two weeks 
resembles that of the girls. Maximal score is not made 
■until seventh day with right hand and on last day with 
left hand. Here the longer period intervening between prac- 
tice periods may cause the sustained interest and there is 
gradual improvement. 

It is also suggested that the initial performance of boys 
represents more practice in this activity. Just how much it 
is not possible to determine. Some questions were asked 
as to previous motor activities but the answers were too 
indirect to be satisfactory. Rubber balls for bouncing 
seemed to be the chief kind with which the girls were ac- 
quainted. In a few cases girls spoke of playing "catch" 
with their young brothers. 

There is certainly an indication that the emotional attitude 
greatly affects progress in learning and that sex differentia- 
tion is most distinct in the affective elements. 



VIII. PREFERENCE IN SIDE OF BODY USED 

In both of the practice series in motor coordination 
preference in hand used was very evident. At this age the 
three types are readily recognized, the decidedly right- 
handed, the practically ambidextrous, and those distinctly 
preferring left hand. In the second class a given hand 
is usually preferred for certain activities, such as writing 
with one hand and throwing a ball with the other. It be- 
comes an important problem of school management to de- 
termine whether the left-handed person should be left alone 
or ambidexterity cultivated. 

Ballard (2) made three investigations into the effect of 
interference with left-handedness, finding the percentage of 
stammerers among the frankly left-handed to be 2%, the 
same as among school children as a whole. But among the 
left-handed who have been forced to write with right hand 
this increases to 17%. He also reports a distinct difference 
in intelligence between the two classes of left-handed chil- 
dren, those upon whom ambidextral training has been forced 
being clearly inferior, though coming as a rule from better 
homes. 

To investigate the preference in side of body used, a 
number of children were examined in the school in which 
the aiming test was conducted. 

All the children of a first grade were taken to the gym- 
nasium, and one child at a time, standing near center of hall, 
was asked to kick a light football to another at the other 
end of room, who in turn should kick it back. The foot 
used was noted. Out of thirty-eight children, two boys and 
one girl used the left foot. One of the boys. Otto, was 
decidedly left-handed, writing with his left hand, and no 
attempt had been made to force him to use right hand. The 
other boy and the girl wrote with right hand and had a 

53 



54 MOTOR ABILITIES OF CHILDREN 

slight balance in favor of right hand in aiming test, though 
on many days the left hand excelled. One left-handed girl, 
Anna, among this group used her right foot. She also 
writes with right hand. Her score in aiming was very low, 
but left hand was slightly superior. 

To discover any preference as to direction in turning, a 
" soldier " game was used. Again we went to the gym- 
nasium so as to have a large space with similar surroundings 
on each side. There were windows on one side only, so the 
back was turned to windows, thus having a blank wall in 
front and at either side. Two straight lines were drawn 
upon the floor in white crayon and the child was asked to 
walk like a soldier from one to the other, turn, and walk 
back again. This was repeated four times. The observer 
stood about five feet directly behind the subject at starting. 
No one was within his field of vision until after he had 
turned. Sometimes there were only two and never more 
than five children were in the gymnasium at one time. Re- 
sults from fifty-five children between the ages of five and 
eight years are as follows : 

The number consistently turning to left was 30; to right 
14. There were— 

5 who turned to left 4 times ; to right i time. 
2 who turned to left 3 times ; to right 2 times. 
2 who turned t'o left 2 times; to right 3 times. 
2 who turned to left i time; to right 4 times. 

Of the three decidedly left-handed subjects as determined 
in aiming, two consistently turned to left, the boy, Otto, 
mentioned in kicking of ball, and the girl, Anna. One boy, 
William, who writes with left hand and made the best left- 
handed score of entire group in aiming, his left hand failing 
only once to excel his right, turned to left only twice out of 
five times. 

Since only 20% of number show inconsistency, it is evi- 
dent that there is decided preference as to direction of turn. 
The effect of training and imitation would have to be con- 
sidered in a more complete analysis. Interference effects 



PREFERENCE IN SIDE OF BODY USED 55 

might explain somewhat the lack of correlation between 
preferred hand and preferred side in turning. The position 
of thumb in clasping of hands, with fingers interlaced, is re- 
ported by adults to be distinctly preferential. There is 
scarcely a dissenting voice as to the awkwardness felt in 
placing the other thumb than desired one on top. Among 
the few adults tested, as a rule, the right-handed person puts 
the left thumb on top and vice versa. This seems to give the 
favored hand a more advantageous position for the clasp- 
ing in which it takes the aggressive part. 

Results from sixty-four children are given. These chil- 
dren were not only asked to clasp hands and position of 
thumbs noted as each one passed slowly by, but in a song 
taught by their teacher they were required to sit with clasped 
hands resting on desks. The observer passed along the 
aisles during the singing of this song to note again the 
manner of clasping. Position of thumb was same in each 
case as in previous clasping. 

28 — R. H. in writing — put R. thumb on top. 
32 — R. H. in writing — put L. thumb on top. 

3 — L. H. in writing — put R. thumb on top. 

I — L. H. in writing — put L. thumb on top. 

There is consistency and preference in form of clasping, but 
the almost equal distribution of right-handed group shows 
no direct correlation with favored hand in other activities. 

The importance of the development of motor activities of 
young children makes the question of motor methods and 
of interference with use of preferred hand a vital one in 
educational theory. While we need much more data as to 
real effects of interference and the advisability of cultivat- 
ing right-handedness, the data set forth certainly leads to the 
conclusion that there is a marked preference as to side of 
body used by an individual in his various activities, even 
such as environmental compulsion or suggestion can not 
explain. 



IX. GENERAL SUMMARY AND CONCLUSIONS 

I. Rate of Voluntary Movement 

Previous research has shown marked increase in rate of 
movement with increasing age. The results we have ob- 
tained for young children compared with those established 
for subjects of more advanced age accord with this finding. 

There is gradual improvement due to practice but great 
irregularity in early trials, the average rate being attained 
by fourth or sixth day but maximal efficiency is not reached 
until late in the series. 

We seem justified in concluding that the initial trial, or 
average of less than five trials, does not give a valid indica- 
tion of actual ability, of fatigue effects, or of sex differences. 
This corresponds to Kelly's (12) conclusion for children 
from four to fourteen years old, that "there is no trust- 
worthy correspondence between the work of the first ten 
seconds and the child's real mental power so far as it may be 
applied to any practical problem in life." 

No direct correlation of fatigue and rate is found, nor 
is there a distinct sex differentiation in loss by fatigue. The 
index of fatigue is greater for use of hand not preferred. 

There is a distinct difference between the sexes in ability 
in tapping test, favoring the girls in this group, which has 
far greater variation among girls with two subjects at each 
extreme, while the boys cluster closely about the average. 
This leads to no generalization concerning sex differences. 

The index of right-handedness for girls is 78% ; for boys, 
79%. Compared with Smedley's (19) 82% at age of nine 
years, 89% at age of eighteen years, and with Wells' (21) 
average index of 90% for adults, this indicates more pro- 
nounced efficiency of right hand in childhood. 

56 



general summary and conclusions 57 

2. Steadiness of Motor Control 

There is great variation in the outcome of this test, with 
shifting superiority from one hand to the other. There is 
evidence of but slight improvement from repetition of test. 

The girls excelled with right hand, the boys with left 
hand. The best individual score in each test was made by 
a boy. 

The index of right-handedness is lower than in tapping 
and varies from test to test, so that it is not very reliable 
as indicating efficiency of either hand. 

3. Reaction Times 

There is marked improvement due to practice in quick- 
ness of response to visual stimulus. The simple reactions 
preceding the discrimination were longer than the dis- 
crimination, those following were shorter. 

Premature responses are more frequent in simple reac- 
tions, due, perhaps, to inhibitory effects of discrimination 
reactions. 

There is an increasingly shortened reaction time with 
increasing age for subjects studied, but averages obtained 
for children approximate much more closely those for adults 
than is shown in results of other motor tests. The three 
subjects from eight to ten years old have quicker reactions 
than the seventeen-year-old subjects tested by Gilbert (8) 
and McDonald (15). 

We find less difference between the simple and dis- 
crimination reaction times than the results of these investi- 
gators show. 

4. Accuracy of Movement 

The rate and amount of improvement in accuracy of 
movement vary considerably for sexes and for groups with 
different intervals between practice. 

The aiming test is most reliable for indicating left-handed- 
ness, the index varying from 73% to 80% for groups having 
no left-handed subjects and reaching 96% for group having 
a subject consistently left-handed. 



58 MOTOR ABILITIES OF CHILDREN 

There is no distinct sex differentiation evidenced by 
average results, except for left hand of two groups which 
particular cases of superiority with left hand explain. 

The sex difference in course of improvement from day to 
day is so great that comparison of groups other than by 
sexes is of little value. 

The girls show a gradual improvement, with irregularities 
in left-hand progress, and maximal efficiency is not attained 
until fourth day or often much later in the series. 

Short and frequent practice periods are more valuable 
for girls. The group having greatest number of throws 
during a practice period with only one practice a week shows 
but little improvement. 

The boys make higher initial scores than final averages in 
all groups except the Once-in-two-weeks group. Maximal 
score was made on first day or in early trials. 

The boys of Once-in-two-weeks group have similar curve 
to girls and maximal score is not made until seventh day 
with right hand and fourth to last day with left hand. 

This suggests better sustained interest of boys with longer 
intervals between practice periods. 

There is an indication of a distinct sex difference in the 
emotional attitude towards motor activities, with more com- 
plete response on part of boys in beginning showing negative 
improvement; but a sustained interest on part of girls, 
resulting in gradual progress. 

5. Preference in Side of Body Used 

There is a decided preference as to hand or foot used in 
free motor activities: in direction of turning and in posi- 
tion of fingers when hands are clasped. 

There is no direct correlation of favored hand with 
favored side used in other activities, but more consistency 
in preference of left-handed group for left side than in 
preference of right-handed group for right side. 

The results for these groups could not be universally ap- 
plied as representative of the motor abilities of children. 



GENERAL SUMMARY AND CONCLUSIONS 59 

They certainly suggest the need of experimental evidence, 
upon which to base the solution of practical educational 
problems. 

If educational guidance is to serve as a basis for vocational 
guidance and such tests are to be applied for selective pur- 
poses, beginnings having already been made in these lines, 
the significance and reliability of such tests are most 
important. 



BIBLIOGRAPHY 

(i) Bagley, W. C. 

On the Correlation of Mental and Motor Ability in 
School Children. Amer. Journal Psy., vol. 12, 
1901, 193-205. 

(2) Ballard, P. B. 

Ambidexterity. Ed. Times, London, Feb., 1916. 

(3) Boas, F. 

The Growth of Children. Sci., 20: 1892, 351, 352. 

(4) Bolton, T. L. 

The Relation of Motor Power to Intelligence. Amer. 
Jour. Psy., 2: 1895, 615, 631. 

(5) Bryan, W. L. 

On the Development of Voluntary Motor Ability. 
Amer. Jour. Psy., Vol. 5, 1892, 123-204. 

(6) Burt, C. and Moore, R. C. 

The Mental Differences between the Sexes. Jour, 
of Ex. Ped., Vol. I, 1911-12, 273-284 and 355- 
388. 

(7) Dresslar, F. B. 

Some Influences Which Affect the Rapidity of Vol- 
untary Movements. Amer. Jour. Psy., Vol. 4, 
1892, 514-527. 

(8) Gilbert, J. A. 

Mental and Physical Development of School Chil- 
dren, stud, from Yale Psy. Lab., Vol. 2, 1894, 
40-100. 

(9) Gilbert, J. A. 

Researches upon School Children and College Stu- 
dents, Univ. Iowa Stud. Psy., i : 1897, 1-39. 

60 



BIBLIOGRAPHY 6 1 

(10) Hancock, J. A. 

A Preliminary Study of Motor Ability. Ped. Sem., 
3: 1894, 9-29. 

(11) Hollingworth, H. L. 

The Influence of Caffein on Mental and Motor Effi- 
ciency. Arch. Psy., Vol. 22, 1912, N. Y. 

(12) Kelly, R. L. 

Psychophysical Tests of Normal and Abnormal Chil- 
dren. Psy. Rev., Vol. 10, 1903. 

(13) Leuba and Hyde. 

An Experiment on Learning to Make Hand Move- 
ments. Psy. Rev., Vol. 12, 351-369. 

(14) Lashley, K. S. 

Practice in Archery — not published. 

(15) McDonald, Arthur. 

Experimental Study of Children. Rep. Com. Ed., 
1897-98, Chaps. XXI and XXII. 

(16) Marsh, H. D. 

The Diurnal Course of Efficiency. Col. Univ. Diss., 
1906. 

(17) Munn. 

Curve of Learning Arch. Psy., No. 12, 37. 

(18) Murphy, H. H. 

Distribution of Practice Periods in Learning. Jour. 
Ed. Psy., March, 191 6. 

(19) Smedley, F. W. 

Report of Department of Child Study and Pedagogic 
Investigation, Rep. Com. Ed., 1902, i: 1095-1138. 
(20)' Thompson, H. B. 

The Mental Traits of Sex. Univ. Chicago, 1903. 
(21) Wells, F. L. 

Normal Performances in Tapping Test, before and 
during Practice, with Special Reference to Fatigue 
Phenomena. Amer. Jour. Psy., 19: 1908, 437- 
483. 



62 MOTOR ABILITIES OF CHILDREN 

(22) Wells, F. L. 

Sex Differences in Tapping Test and Interpretation. 
Amer. Jour. Psy., Vol. 20, 1909, 353-363. 

(23) Woolley, H. T. and Fischer, C. R. 

Mental and Physical Measurements of Working 
Children. Psy. Mon., i, Vol. 18, 1914, 200-246. 

(24) Whipple, G. M. 

Manual of Physical and Mental Tests. 1914, Part I. 
Baltimore, Warwick and York. 



VITA 

Buford Jennette Johnson was born in Thomson, Georgia, 
on the twenty-third of August, eighteen hundred and eighty. 
She received her A.B. degree from LaGrange College in 
eighteen hundred and ninety-five. The following year she 
attended courses in Education at the Georgia State Normal 
School. 

After teaching in the Public Schools of Thomson and 
Brunswick, Georgia, she became an Instructor in the de- 
partment of Mathematics of LaGrange College, and later an 
associate in Education and Psychology. 

In January, nineteen hundred and fourteen she entered 
The Johns Hopkins University, registering for major work 
in Education, with Psychology and Mathematics as subor- 
dinate subjects. She held a Hopkins scholarship for the 
following year and received her Master's degree in June, 
nineteen hundred and fifteen. 

The George Peabody Scholarship in Education was 
awarded to her for the scholastic year nineteen hundred and 
fifteen-sixteen. 



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